Rachel posted on Thursday, March 16, 2017 - 11:51 am
Dear Dr. Muthén,
I ran a LGC model with 3 exogenous variables (2 observed variables and their product term), predicting the latent slope and latent intercept.
I have found code to plot: - an interaction between observed variables predicting an observed variable - an interaction between latent variables predicting a latent variable but am unsure whether either of these would be appropriate for an interaction between observed variables predicting latent variables, particularly a latent intercept?
I am only concerned with interpreting the interaction predicting the latent intercept.
1) Where can I find the code to plot the interaction of 2 observed variables predicting a latent intercept (plotting 3 groups the Aiken & West way)?
2) What would be the code to significance test the simple slopes plotted?
3) Is there anything to be mindful of regarding interpreting an interaction predicting a latent intercept? Or can the plot be interpreted like any other interaction between continuous variables, plotted for groups at the mean and +/- 1SD (just framed instead in terms of where subjects start/scores at Time 1, e.g., cases 1SD above the mean for X1 were associated with high Y scores at T1 regardless of level of X2, but for cases 1SD below the mean of X1, high levels of X2 were associated with high scores in Y at T1)?